3,320 research outputs found
Transcriptional profiling of Arabidopsis heat shock proteins and transcription factors reveals extensive overlap between heat and non-heat stress response pathways
<p>Abstract</p> <p>Background</p> <p>The heat shock response of <it>Arabidopsis thaliana </it>is dependent upon a complex regulatory network involving twenty-one known transcription factors and four heat shock protein families. It is known that heat shock proteins (Hsps) and transcription factors (Hsfs) are involved in cellular response to various forms of stress besides heat. However, the role of Hsps and Hsfs under cold and non-thermal stress conditions is not well understood, and it is unclear which types of stress interact least and most strongly with Hsp and Hsf response pathways. To address this issue, we have analyzed transcriptional response profiles of <it>Arabidopsis </it>Hsfs and Hsps to a range of abiotic and biotic stress treatments (heat, cold, osmotic stress, salt, drought, genotoxic stress, ultraviolet light, oxidative stress, wounding, and pathogen infection) in both above and below-ground plant tissues.</p> <p>Results</p> <p>All stress treatments interact with Hsf and Hsp response pathways to varying extents, suggesting considerable cross-talk between heat and non-heat stress regulatory networks. In general, Hsf and Hsp expression was strongly induced by heat, cold, salt, and osmotic stress, while other types of stress exhibited family or tissue-specific response patterns. With respect to the Hsp20 protein family, for instance, large expression responses occurred under all types of stress, with striking similarity among expression response profiles. Several genes belonging to the Hsp20, Hsp70 and Hsp100 families were specifically upregulated twelve hours after wounding in root tissue, and exhibited a parallel expression response pattern during recovery from heat stress. Among all Hsf and Hsp families, large expression responses occurred under ultraviolet-B light stress in aerial tissue (shoots) but not subterranean tissue (roots).</p> <p>Conclusion</p> <p>Our findings show that Hsf and Hsp family member genes represent an interaction point between multiple stress response pathways, and therefore warrant functional analysis under conditions apart from heat shock treatment. In addition, our analysis revealed several family and tissue-specific heat shock gene expression patterns that have not been previously described. These results have implications regarding the molecular basis of cross-tolerance in plant species, and raise new questions to be pursued in future experimental studies of the <it>Arabidopsis </it>heat shock response network.</p
Multidimensional Students' Life Satisfaction Scale: translation into Brazilian Portuguese and cross-cultural adaptation
The Nernst effect and the boundaries of the Fermi liquid picture
Following the observation of an anomalous Nernst signal in cuprates, the
Nernst effect was explored in a variety of metals and superconductors during
the past few years. This paper reviews the results obtained during this
exploration, focusing on the Nernst response of normal quasi-particles as
opposed to the one generated by superconducting vortices or by short-lived
Cooper pairs. Contrary to what has been often assumed, the so-called Sondheimer
cancelation does not imply a negligible Nernst response in a Fermi liquid. In
fact, the amplitude of the Nernst response measured in various metals in the
low-temperature limit is scattered over six orders of magnitude. According to
the data, this amplitude is roughly set by the ratio of electron mobility to
Fermi energy in agreement with the implications of the semi-classical transport
theory.Comment: Final version, Topical review for JPC
Applicability, potential and limitations of staff-centred energy conservation initiatives in English hospitals
Increasing energy costs and climate change legislation have prompted efforts to reduce energy consumption in UK hospitals. In addition to technological conservation strategies focussing on buildings and building services, staff-centred initiatives such as energy awareness campaigns are increasingly being considered by National Health Service (NHS) Trusts due to their potential cost-effectiveness. However, hospitals are complex buildings with unique energy requirements and it is unclear to what extent these requirements are influenced by clinical staff. This paper combines a review of staff-centred energy conservation initiatives in organisations in general and in hospitals in particular with the results of a survey-based study among NHS energy managers (N=70). The study findings highlight that staff-centred energy conservation initiatives are currently of interest to a majority of NHS trusts in England and may become an increasingly important part of carbon reduction strategies in hospitals in the future. Policy assumptions regarding their savings potential, however, appear to be undifferentiated and it seems advisable to relate behavioural efforts more closely to the physical context of the respective hospital building and its service infrastructure as well as the healthcare processes relevant to different departments
Molecular characterisation of congenital myasthenic syndromes in Southern Brazil
Objective To perform genetic testing of patients with congenital myasthenic syndromes (CMS) from the Southern Brazilian state of Parana. Patients and methods Twenty-five CMS patients from 18 independent families were included in the study. Known CMS genes were sequenced and restriction digest for the mutation RAPSN p.N88K was performed in all patients. Results We identified recessive mutations of CHRNE in ten families, mutations in DOK7 in three families and mutations in COLQ, CHRNA1 and CHRNB1 in one family each. The mutation CHRNE c. 70insG was found in six families. We have repeatedly identified this mutation in patients from Spain and Portugal and haplotype studies indicate that CHRNE c. 70insG derives from a common ancestor. Conclusions Recessive mutations in CHRNE are the major cause of CMS in Southern Brazil with a common mutation introduced by Hispanic settlers. The second most common cause is mutations in DOK7. The minimum prevalence of CMS in Parana is 0.18/100 000
Molecular characterisation of congenital myasthenic syndromes in Southern Brazil
Objective To perform genetic testing of patients with congenital myasthenic syndromes (CMS) from the Southern Brazilian state of Parana. Patients and methods Twenty-five CMS patients from 18 independent families were included in the study. Known CMS genes were sequenced and restriction digest for the mutation RAPSN p.N88K was performed in all patients. Results We identified recessive mutations of CHRNE in ten families, mutations in DOK7 in three families and mutations in COLQ, CHRNA1 and CHRNB1 in one family each. The mutation CHRNE c. 70insG was found in six families. We have repeatedly identified this mutation in patients from Spain and Portugal and haplotype studies indicate that CHRNE c. 70insG derives from a common ancestor. Conclusions Recessive mutations in CHRNE are the major cause of CMS in Southern Brazil with a common mutation introduced by Hispanic settlers. The second most common cause is mutations in DOK7. The minimum prevalence of CMS in Parana is 0.18/100 000
Equation of state and QCD transition at finite temperature
We calculate the equation of state in 2+1 flavor QCD at finite temperature
with physical strange quark mass and almost physical light quark masses using
lattices with temporal extent Nt=8. Calculations have been performed with two
different improved staggered fermion actions, the asqtad and p4 actions.
Overall, we find good agreement between results obtained with these two O(a^2)
improved staggered fermion discretization schemes. A comparison with earlier
calculations on coarser lattices is performed to quantify systematic errors in
current studies of the equation of state. We also present results for
observables that are sensitive to deconfining and chiral aspects of the QCD
transition on Nt=6 and 8 lattices. We find that deconfinement and chiral
symmetry restoration happen in the same narrow temperature interval. In an
Appendix we present a simple parametrization of the equation of state that can
easily be used in hydrodynamic model calculations. In this parametrization we
also incorporated an estimate of current uncertainties in the lattice
calculations which arise from cutoff and quark mass effects. We estimate these
systematic effects to be about 10 MeVComment: 31 pages, 24 EPS-figure
Water in the Near IR spectrum of Comet 8P/Tuttle
High resolution spectra of Comet 8P/Tuttle were obtained in the frequency
range 3440.6-3462.6 cm-1 on 3 January 2008 UT using CGS4 with echelle grating
on UKIRT. In addition to recording strong solar pumped fluorescent (SPF) lines
of H2O, the long integration time (152 miutes on target) enabled eight weaker
H2O features to be assigned, most of which had not previously been identified
in cometary spectra. These transitions, which are from higher energy upper
states, are similar in character to the so-called 'SH' lines recorded in the
post Deep Impact spectrum of comet Tempel 1 (Barber et al., 2007). We have
identified certain characteristics that these lines have in common, and which
in addition to helping to define this new class of cometary line, give some
clues to the physical processes involved in their production. Finally, we
derive an H2O rotational temperature of 62+/- K and a water production rate of
(1.4+/-0.3)E28 molecules/s.Comment: Paper has been accepted for publication by MNRAS (11/06/09
Numerical evolution of Brill waves
We report a numerical evolution of axisymmetric Brill waves. The numerical
algorithm has new features, including (i) a method for keeping the metric
regular on the axis and (ii) the use of coordinates that bring spatial infinity
to the edge of the computational grid. The dependence of the evolved metric on
both the amplitude and shape of the initial data is found.Comment: added more discussion of results and several reference
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